Biodegradable polyesteramide and a process of preparing

ABSTRACT

Biodegradable polyesteramides as defined in the specification obtained by reacting a mixture consisting essentially of 
     (a1) from 95 to 99.9% by weight of a polyesteramide, 
     (a2) from 0.1 to 5% by weight of a divinyl ether, and 
     (a3) from 0 to 5 mol % of compound D as defined in the specification, and other biodegradable polymers and thermoplastic molding compositions, processes for the preparation thereof, the use thereof for producing biodegradable moldings, and adhesives, biodegradable moldings obtained from the polymers and molding compositions according to the invention.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to biodegradable polyesteramides Q1 with amolecular weight (M_(n)) in the range from 5,000 to 50,000 g/mol, aviscosity number in the range from 30 to 450 g/ml (measured ino-dichlorobenzene/phenol (50/50 ratio by weight) at a concentration of0.5% by weight of polyesteramide Q1 at 25° C.) and a melting point inthe range from 50 to 220° C., obtainable by reacting a mixtureconsisting essentially of

(a1) from 95 to 99.9% by weight of a polyesteramide P1 obtainable byreacting a mixture consisting essentially of

(b1) a mixture consisting essentially of

35-95 mol % of adipic acid or ester-forming derivatives thereof ormixtures thereof,

5-65 mol % of terephthalic acid or ester-forming derivatives thereof ormixtures thereof, and

0-5 mol % of a compound containing sulfonate groups, where the total ofthe individual mole percentages is 100 mol %, and

(b2) a mixture consisting essentially of

(b21) 99.5-0.5 mol % of a dihydroxy compound selected from the groupconsisting of C₂ -C₆ -alkanediols and C₅ -C₁₀ -cycloalkanediols,

(b22) 0.5-99.5 mol % of an amino-C₂ -C₁₂ -alkanol or of an amino-C₅ -C₁₀-cycloalkanol, and

(b23) 0-50 mol % of a diamino-C₁ -C₈ -alkane,

(b24) 0-50 mol % of a 2,2'-bisoxazoline of the general formula I##STR1## where R¹ is a single bond, a (CH₂)_(q) -alkylene group withq=2, 3 or 4, or a phenylene group, where the total of the individualmole percentages is 100 mol %,

and where the molar ratio of (b1) to (b2) is chosen in the range from0.4:1 to 1.5:1,

with the proviso that the polyesteramides P1 have a molecular weight(M_(n)) in the range from 4,000 to 40,000 g/mol, a viscosity number inthe range from 30 to 450 g/ml (measured in o-dichlorobenzene/phenol(50/50 ratio by weight) at a concentration of 0.5% by weight ofpolyesteramide P1 at 25° C.) and a melting point in the range from 50 to220° C., and with the further proviso that from 0 to 5 mol %, based onthe molar amount of component (a1) used, of a compound D with at leastthree groups capable of ester formation are used to prepare thepolyesteramides P1,

(a2) from 0.1 to 5% by weight of a divinyl ether C1 and

(a3) from 0 to 5 mol %, based on component (b1) from the preparation ofP1, of compound D.

The invention furthermore relates to polymers and biodegradablethermoplastic molding compositions as claimed in the dependent claims,processes for the preparation thereof, the use thereof for producingbiodegradable moldings and adhesives, biodegradable moldings, foams andblends with starch, obtainable from the polymers and moldingcompositions according to the invention.

2. Description of Related Art

Polymers which are biodegradable, ie. decompose under environmentalinfluences in an appropriate and demonstrable time span, have been knownfor some time. This degradation usually takes place by hydrolysis and/oroxidation, but predominantly by the action of microorganisms such asbacteria, yeasts, fungi and algae. Y. Tokiwa and T. Suzuki (Nature, 270,(1977) 76-78) describe the enzymatic degradation of aliphaticpolyesters, for example including polyesters based on succinic acid andaliphatic diols.

EP-A 565,235 describes aliphatic copolyesters containing [--NH--C(O)O--]groups (urethane units). The copolyesters of EP-A 565,235 are obtainedby reacting a prepolyester, which is obtained by reacting essentiallysuccinic acid and an aliphatic diol, with a diisocyanate, preferablyhexamethylene diisocyanate. The reaction with the diisocyanate isnecessary according to EP-A 565,235 because the polycondensation aloneresults only in polymers with molecular weights such that they displayunsatisfactory mechanical properties. A crucial disadvantage is the useof succinic acid or ester derivatives thereof to prepare thecopolyesters because succinic acid and derivatives thereof are costlyand are not available in adequate quantity on the market. In addition,the polyesters prepared using succinic acid as the only acid componentare degraded only extremely slowly.

Chain extension can, according to EP-A 534 295, also be advantageouslyachieved by reaction with divinyl ethers.

WO 92/13019 discloses copolyesters based on predominantly aromaticdicarboxylic acids and aliphatic diols, where at least 85 mol % of thepolyester diol residue comprises a terephthalic acid residue. Thehydrophilicity of the copolyester can be increased and the crystallinitycan be reduced by modifications such as incorporation of up to 2.5 mol %of metal salts of 5-sulfoisophthalic acid or short-chain ether diolsegments such as diethylene glycol. This is said in WO 92/13019 to makethe copolyesters biodegradable. However, a disadvantage of thesecopolyesters is that biodegradation by microorganisms was notdemonstrated, on the contrary only the behavior towards hydrolysis inboiling water or, in some cases, also with water at 60° C. was carriedout.

According to Y. Tokiwa and T. Suzuki, (Nature, 270 (1977), and J. Appl.Polymer Science, 26 (1981), 441-448), it can be assumed that polyestersbuilt up substantially from aromatic dicarboxylic acid units andaliphatic diols, such as PET (polyethylene terephthalate) and PBT(polybutylene terephthalate), cannot be degraded enzymatically. Thisalso applies to copolyesters containing blocks built up from aromaticdicarboxylic acid units and aliphatic diols.

In addition, Y. Tokiwa, T. Suzuki and T. Ando (J. of Appl. Polym. Sci.24 (1979) 1701-1711) prepared polyesteramides and blends ofpolycaprolactone and various aliphatic polyamides such as polyamide-6,polyamide-66, polyamide-11, polyamide-12 and polyamide-69 by meltcondensation and investigated their biodegradability by lipases. It wasfound that the biodegradability of such polyesteramides depends greatlyon whether there is a predominantly random distribution of the amidesegments or, for example, a block structure. In general, amide segmentstend to reduce the rate of biodegradation by lipases.

However, the crucial factor is that no lengthy amide blocks are present,because it is known from Plant Cell Physiol. 7 (1966) 93, J. Biochem. 59(1966) 537 and Agric. Biol. Chem. 39 (1975) 1219 that the usual alipaticand aromatic polyamides are biodegradable at the most only whenoligomers, otherwise not.

Witt et al. (handout for a poster at the International Workshop of theRoyal Institute of Technology, Stockholm, Sweden, Apr. 21-23, 1994)describe biodegradable copolyesters based on 1,3-propanediol,terephthalic ester and adipic or sebacic acid. A disadvantage of thesecopolyesters is that moldings produced therefrom, especially sheets,have inadequate mechanical properties.

BRIEF SUMMARY OF THE INVENTION

It is an object of the present invention to provide polymers which aredegradable biologically, ie. by microorganisms, and which do not havethese disadvantages. The intention was, in particular, that the polymersaccording to the invention be preparable from known and low-cost monomerunits and be insoluble in water. It was furthermore the intention thatit be possible to obtain products tailored for the desired usesaccording to the invention by specific modifications such as chainextension, incorporation of hydrophilic groups and groups having abranching action. The aim was moreover that the biodegradation bymicroorganisms should not be achieved at the expense of the mechanicalproperties in order not to restrict the number of applications.

We have found that this object is achieved by the polymers andthermoplastic molding compositions defined at the outset.

We have furthermore found processes for the preparation thereof, the usethereof for producing biodegradable moldings and adhesives, andbiodegradable moldings, foams, blends with starch and ahdesivesobtainable from the polymers and molding compositions according to theinvention.

DETAILED DESCRIPTION OF THE INVENTION

The biodegradable polyesteramides Q1 according to the invention have amolecular weight (M_(n)) in the range from 5,000 to 50,000, preferablyfrom 6,000 to 50,000, particularly preferably from 8,000 to 35,000,g/mol, a viscosity number in the range from 30 to 450, preferably from50 to 400, g/ml (measured in o-dichlorobenzene/phenol (50/50 ratio byweight) at a concentration of 0.5% by weight of polyesteramide Q1 at 25°C.), and a melting point in the range from 50 to 220° C., preferablyfrom 60 to 220° C.

The polyesteramides Q1 are obtained according to the invention byreacting a mixture consisting essentially of

a1) from 95 to 99.9, preferably from 96 to 99.8, particularly preferablyfrom 97 to 99.65, % by weight of a polyesteramide P1,

a2) from 0.1 to 5, preferably 0.2-4, particularly preferably from 0.35to 3, % by weight of a divinyl ether C1 and

a3) from 0 to 5, preferably from 0 to 4, mol % based on component (b1)from the preparation of P1, of a compound D.

Preferred polyesteramides P1 have a molecular weight (M_(n)) in therange from 4,000 to 40,000, preferably from 5,000 to 35,000,particularly preferably from 6,000 to 30,000, g/mol, a viscosity numberin the range from 30 to 350, preferably from 50 to 300, g/ml (measuredin o-dichlorobenzene/phenol (50/50 ratio by weight) at a concentrationof 0.5% by weight of polyesteramide P1 at 25° C.), and a melting pointin the range from 50 to 220° C., preferably from 60 to 220° C.

The polyesteramides P1 are obtained as a rule by reacting a mixtureconsisting essentially of

(b1) a mixture consisting essentially of

35-95, preferably from 45 to 80, mol % of adipic acid or ester-formingderivatives thereof, in particular the di-C₁ -C₆ -alkyl esters such asdimethyl, diethyl, dipropyl, dibutyl, dipentyl and dihexyl adipate, ormixtures thereof, preferably adipic acid and dimethyl adipate, ormixtures thereof,

5-65, preferably 20-55, mol %, of terephthalic acid or ester-formingderivatives thereof, in particular the di-C₁ -C₆ -alkyl esters such asdimethyl, diethyl, dipropyl, dibutyl, dipentyl or dihexyl terephthalate,or mixtures thereof, preferably terephthalic acid and dimethylterephthalate, or mixtures thereof, and

0-5, preferably from 0 to 3, particularly preferably from 0.1 to 2, mol% of a compound containing sulfonate groups,

where the total of the individual mole percentages is 100 mol %, and

(b2) a mixture consisting essentially of

(b21) 99.5-0.5, preferably 99.5-50, particularly preferably 98.0-70, mol% of a dihydroxy compound selected from the group consisting of C₂ -C₆-alkanediols and C₅ -C₁₀ -cycloalkanediols,

(b22) 0.5-99.5, preferably 0.5-50, particularly preferably 1 to 30, mol% of an amino-C₂ -C₁₂ -alkanol or of an amino-C₅ -C₁₀ -cycloalkanol, and

(b23) 0-50, preferably from 0 to 35, particularly preferably from 0.5 to30, mol % of a diamino-C₁ -C₈ -alkane,

(b24) 0-50, preferably 0-30, particularly preferably 0.5-20, of a2,2'-bisoxazoline of the general formula I ##STR2## where R¹ is a singlebond, an ethylene, n-propylene or n-butylene group, or a phenylene group, and R¹ is particularly preferably n-butylene, where the total of theindividual mole percentages is 100 mol %,

where the molar ratio of (b1) to (b2) is chosen in the range from 0.4:1to 1.5:1, preferably from 0.6:1 to 1.1:1.

The compound containing sulfonate groups which is normally employed isan alkali metal or alkaline earth metal salt of a dicarboxylic acidcontaining sulfonate groups, or the ester-forming derivatives thereof,preferably alkali metal salts of 5-sulfo-isophthalic acid or mixturesthereof, particularly preferably the sodium salt.

The dihydroxy compounds (b21) employed according to the invention areselected from the group consisting of C₂ -C₆ -alkanediols, C₅ -C₁₀-cycloalkanediols, the latter also including 1,2-cyclohexanedimethanoland 1,4-cyclohexanedimethanol, such as ethylene glycol, 1,2- and1,3-propanediol, 1,2- and 1,4-butanediol, 1,5-pentanediol or1,6-hexanediol, in particular ethylene glycol, 1,3-propanediol and1,4-butanediol, cyclopentanediol, 1,4-cyclohexanediol and mixturesthereof.

The amino-C₂ -C₁₂ -alkanol or amino-C₅ -C₁₀ -cycloalkanol (component(b22)), which is intended to include 4-aminocyclohexanemethanol, whichis preferably used is an amino-C₂ -C₆ -alkanol such as 2-aminoethanol,3-aminopropanol, 4-aminobutanol, 5-aminopentanol or 6-aminohexanol, oramino-C₅ -C₆ -cycloalkanols such as aminocyclopentanol andaminocyclohexanol or mixtures thereof.

The diamino-C₁ -C₈ -alkane preferably employed is a diamino-C₄ -C₆-alkane such as 1,4-diaminobutane, 1,5-diaminopentane and1,6-diaminohexane (hexamethylenediamine, HMD).

The compounds of the general formula I (component b24) are, as a rule,obtainable by the process of Angew. Chem. int. Edit. 11 (1972) 287-288.

From 0 to 5, preferably from 0.01 to 4 mol %, based on component (a1),of at least one compound D with at least three groups capable of esterformation are used according to the invention.

The compounds D preferably contain three to ten functional groupscapable of forming ester linkages. Particularly preferred compounds Dhave three to six functional groups of this type in the molecule, inparticular three to six hydroxyl groups and/or carboxyl groups. Exampleswhich may be mentioned are:

tartaric acid, citric acid, malic acid;

trimethylolpropane, trimethylolethane;

pentaerythritol;

polyethertriols;

glycerol;

trimesic acid;

trimellitic acid or anhydride;

pyromellitic acid or dianhydride and

hydroxyisophthalic acid.

When compounds D which have a boiling point below 200° C. are used inthe preparation of the polyesters P1, a proportion may distil out of thepolycondensation mixture before the reaction. It is therefore preferredto add these compounds in an early stage of the process, such as thetransesterification or esterification stage, in order to avoid thiscomplication and in order to achieve the maximum possible uniformity oftheir distribution within the polycondensate.

In the case of compounds D which boil above 200° C., they can also beemployed in a later stage of the process.

By adding the compound D it is possible, for example, to alter the meltviscosity in a desired manner, to increase the impact strength and toreduce the crystallinity of the polymers or molding compositionsaccording to the invention.

The preparation of the biodegradable polyesteramides P1 is known inprinciple (Sorensen and Campbell, Preparative Methods of PolymerChemistry, Interscience Publishers, Inc., New York, 1961, pages 111-127;Kunststoff-Handbuch, volume 3/1, Carl Hanser Verlag, Munich, 1992, pages15-23 (preparation of polyesteramides); WO 92/13019; EP-A 568,593; EP-A565,235; EP-A 28,687 (preparation of polyesters); Encycl. of Polym.Science and Eng., vol. 12, 2nd Ed., John Wiley & Sons, 1988, pages 1-75,especially pages 59 and 60; GB 818157; GB 1010916; GB 1115512), so thatdetails on this are superfluous.

Thus, for example, the reaction of dimethyl esters of component (b1)with component (b2) can be carried out at from 160 to 230° C. in themelt under atmospheric pressure, advantageously under an inert gasatmosphere.

In a preferred embodiment, initially the required amino hydroxy compound(b22) is reacted with component (b1), preferably terephthalic acid,dimethyl terephthalate, adipic acid, di-C₂ -C₆ -alkyl adipate, succinicanhydride, phthalic anhydride, in a molar ratio of 2:1.

In another preferred embodiment, the required diamine compound (b23) isreacted with component (b1), preferably terephthalic acid, dimethylterephthalate, adipic acid, di-C₂ -C₆ -alkyl adipate, succinicanhydride, phthalic anhydride, in a molar ratio of at least 0.5:1,preferably 0.5:1.

In another preferred embodiment, the required 2,2'-bisoxazoline (b24) isreacted with component (b1), preferably terephthalic acid, dimethylterephthalate, adipic acid, di-C₂ -C₆ -alkyl adipate, succinicanhydride, phthalic anhydride, in a molar ratio of at least 0.5:1,preferably 0.5:1.

In the case of a mixture of at least one amino hydroxy compound (b22)and at least one diamino compound (b23) and at least one2,2'-bisoxazoline (b24), these are expediently reacted with component(b1) in the molar amounts stated in the abovementioned preferredembodiments.

In the preparation of the biodegradable polyesteramide P1, it isadvantageous to use a molar excess of component (b2) relative tocomponent b1, for example up to 21/2 times, preferably up to 1.67 times.

The biodegradable polyesteramide P1 is normally prepared with theaddition of suitable conventional catalysts (Encycl. of Polym. Scienceand Eng., vol. 12, 2nd Ed., John Wiley & Sons, 1988, pages 1-75, inparticular pages 59 and 60; GB 818157; GB 1010916; GB 1115512), forexample metal compounds based on the following elements such as Ti, Ge,Zn, Fe, Mn, Co, Zr, V, Ir, La, Ce, Li, and Ca, preferably organometalliccompounds based on these metals, such as salts of organic acids,alkoxides, acetylacetonates and the like, particularly preferably basedon lithium, zinc, tin and titanium.

When dicarboxylic acids or anhydrides thereof are used as component(b1), esterification thereof with component (b2) can take place before,at the same time as or after the transesterification. In a preferredembodiment, the process described in DE-A 23 26 026 for preparingmodified polyalkylene terephthalates is used.

After the reaction of components (b1) and (b2), the polycondensation iscarried out as far as the desired molecular weight, as a rule underreduced pressure or in a stream of inert gas, for example of nitrogen,with further heating to from 180 to 260° C.

In order to prevent unwanted degradation and/or side reactions, it isalso possible in this stage of the process if required to addstabilizers. Examples of such stabilizers are the phosphorus compoundsdescribed in EP-A 13 461, U.S. Pat. No. 4,328,049 or in B. Fortunato etal., Polymer Vol. 35, No. 18, pages 4006-4010, 1994,Butterworth-Heinemann Ltd. These may also in some cases act asinactivators of the catalysts described above. Examples which may bementioned are: organophosphites, phosphonous acid and phosphorous acid.Examples of compounds which act only as stabilizers are: trialkylphosphites, triphenyl phosphite, trialkyl phosphates, triphenylphosphate and tocopherol (vitamin E; obtainable as Uvinul® 2003AO (BASF)for example).

On use of the biodegradable copolymers, for example in the packagingsector, eg. for foodstuffs, it is as a rule desirable to select thelowest possible content of catalyst employed and not to employ any toxiccompounds. In contrast to other heavy metals such as lead, tin,antimony, cadmium, chromium, etc., titanium and zinc compounds arenon-toxic as a rule (Sax Toxic Substance Data Book, Shizuo Fujiyama,Maruzen, K. K., 360 S. (cited in EP-A 565,235), see also Rompp ChemieLexikon Vol. 6, Thieme Verlag, Stuttgart, N.Y., 9th Edition, 1992, pages4626-4633 and 5136-5143). Examples which may be mentioned are:dibutoxydiacetoacetoxytitanium, tetrabutyl orthotitanate and zinc(II)acetate.

The ratio by weight of catalyst to biodegradable polyesteramide P1 isnormally in the range from 0.01:100 to 3:100, preferably from 0.05:100to 2:100, it also being possible to employ smaller quantities, such as0.0001:100, in the case of highly active titanium compounds.

The catalyst can be employed right at the start of the reaction,directly shortly before the removal of the excess diol or, if required,also distributed in a plurality of portions during the preparation ofthe biodegradable polyesteramides P1. It is also possible if required toemploy different catalysts or mixtures thereof.

It is possible according to observations to date to employ as divinylethers C1 all conventional and commercially obtainable divinyl ethers.Preferably used divinyl ethers are selected from the group consisting of1,4-butanediol divinyl ether, 1,6-hexanediol divinyl ether and1,4-cyclohexanedimethanol divinyl ether.

The reaction, which is normally catalyzed by cations, of thepolyesteramides P1 with the divinyl ether C1 preferably takes place inthe melt, it being necessary to take care that, if possible, no sidereactions which may lead to crosslinking or gel formation occur. In aparticular embodiment, the reaction is normally carried out at from 90to 230, preferably from 100 to 200° C., with the addition of the divinylether advantageously taking place in a plurality of portions orcontinuously.

If required it is also possible to carry out the reaction of thepolyesteramides P1 with the divinyl ethers C1 in the presence ofconventional inert solvents such as toluene, methyl ethyl ketone,tetrahydrofuran (THF) or ethyl acetate or mixtures thereof, in whichcase the reaction is as a rule carried out at from 80 to 200, preferablyfrom 90 to 150° C.

The reaction with the divinyl ethers C1 can be carried out batchwise orcontinuously, for example in stirred vessels, reaction extruders orscrew mixing heads.

It is also possible to employ in the reaction of the polyesteramides P1with the divinyl ethers C1 conventional catalysts which are disclosed inthe prior art (for example those described in EP-A 534295). Exampleswhich may be mentioned are: organic carboxylic acids such as oxalicacid, tartaric acid and citric acid, it again being necessary to takecare that, if possible, the compounds employed are not toxic.

Although the theoretical optimum for the reaction of P1 with divinylether C1 is a 1:1 molar ratio of vinyl ether functionality to P1 endgroup (polyesteramides P1 with predominantly hydroxyl end groups arepreferred), the reaction can also be carried out without technicalproblems at molar ratios of from 1:3 to 1.5:1. With molar ratios of >1:1it is possible if desired to add, during the reaction or else after thereaction, a chain extender selected from the components (b2), preferablya C₂ -C₆ -diol.

The biodegradable polymers T1 according to the invention have amolecular weight (M_(n)) in the range from 6,000 to 50,000, preferablyfrom 8,000 to 40,000, particularly preferably from 8,000 to 35,000,g/mol, a viscosity number in the range from 30 to 450, preferably from50 to 400, g/ml (measured in o-dichlorobenzene/phenol (50/50 ratio byweight) at a concentration of 0.5% by weight of polymer T1 at 25° C.)and a melting point in the range from 50 to 255, preferably from 60 to255° C.

The biodegradable polymers T1 are obtained according to the invention byreacting the polyesteramides Q2 with

(d1) 0.1-5, preferably from 0.2 to 4, particularly preferably from 0.3to 2.5, % by weight, based on polyesteramide Q2, of divinyl ether C1 andwith

(d2) 0-5, preferably from 0 to 4, mol %, based on component (b1) fromthe preparation of polyesteramide Q2 via polyesteramide P1, of compoundD.

This normally results in a chain extension, with the resulting polymerchains preferably having a block structure.

Preferred biodegradable polyesteramides Q2 have a molecular weight(M_(n)) in the range from 5,000 to 50,000, preferably from 6,000 to40,000, particularly preferably from 8,000 to 35,000, g/mol, a viscositynumber in the range from 30 to 450, preferably from 50 to 400, g/ml(measured in o-dichlorobenzene/phenol (50/50 ratio by weight) at aconcentration of 0.5% by weight of polyesteramide Q2 at 25° C.) and amelting point in the range from 50 to 235, preferably from 60 to 235° C.

The polyesteramides Q2 are obtained in general by reacting a mixtureconsisting essentially of

(c1) polyesteramide P1,

(c2) 0.01-50, preferably from 0.1 to 40, % by weight, based on (c1), ofamino carboxylic acid B1,

where the amino carboxylic acid B1 is selected from the group consistingof the natural amino acids, polyamides with a molecular weight notexceeding 18,000 g/mol, preferably not exceeding 15,000 g/mol,obtainable by polycondensation of a dicarboxylic acid with 4 to 6 carbonatoms and a diamine with 4 to 10 carbon atoms and compounds which aredefined by the formulae IIa or IIb ##STR3## where p is an integer from 1to 1,500, preferably from 1 to 1,000, and r is 1, 2, 3 or 4, preferably1 and 2, and G is a radical selected from the group consisting ofphenylene, --(CH₂)_(n) --, where n is an integer from 1 to 12,preferably 1, 5 or 12, --C(R²)H-- and --C(R²)HCH₂, where R² is methyl orethyl, and polyoxazolines of the general formula III ##STR4## where R³is hydrogen, C₁ -C₆ -alkyl, C₅ -C₈ -cycloalkyl, phenyl which isunsubstituted or substituted up to three times by C₁ -C₄ -alkyl groups,or tetrahydrofuryl,

(c3) 0-5, preferably from 0 to 4, mol %, based on component (b1) fromthe preparation of P1, of compound D.

The natural amino acids which are preferably used are the following:glycine, aspartic acid, glutamic acid, alanine, valine, leucine,isoleucine, tryptophan, phenylalanine and oligo- and polymers obtainabletherefrom, such as polyaspartimides and polyglutamimides, particularlypreferably glycine.

The polyamides employed are those obtainable by polycondensation of adicarboxylic acid with 4 to 6 carbon atoms and a diamine with 4 to 10carbon atoms, such as tetramethylenediamine, pentamethylenediamine,hexamethylenediamine, heptamethylenediamine, octamethylenediamine,nonamethylenediamine and decamethylenediamine.

Preferred polyamides are polyamide -46, polyamide-66 and polyamide-610.These polyamides are generally prepared by conventional methods. It isself-evident that these polyamides can contain conventional additivesand auxiliaries and that these polyamides can be prepared by usingappropriate regulators.

The polyoxazolines III are, as a rule, prepared by the process describedin DE-A 1 206 585.

Particularly preferred compounds defined by the formulae IIa or IIb are:6-aminohexanoic acid, caprolactam, laurolactam and the oligomers andpolymers thereof with a molecular weight not exceeding 18,000 g/mol.

The reaction of the polyesteramides P1 with the amino carboxylic acidB1, if required in the presence of compound D, preferably takes place inthe melt at from 120 to 260° C. under an inert gas atmosphere, ifdesired also under reduced pressure. The procedure can be both batchwiseand continuous, for example in stirred vessels or (reaction) extruders.

The reaction rate can, if required, be increased by adding conventionaltransesterification catalysts (see those described hereinbefore for thepreparation of the polyesteramides P1).

When components B1 with higher molecular weights, for example with a pabove 10 (ten) are used, it is possible to obtain, by reaction with thepolyesteramides P1 in stirred vessels or extruders, the desired blockstructures by the choice of the reaction conditions such as temperature,buildup time and addition of transesterification catalysts such as theabovementioned. Thus, J. of Appl. Polym. Sci., 32 (1986) 6191-6207 andMakromol. Chemie 136 (1970) 311-313 disclose that in the reaction in themelt it is possible to obtain from a blend by transesterificationreactions initially block copolymers and then random copolymers.

The polymers T1 are, as a rule, prepared in a similar way to thepolyesteramides Q1.

The biodegradable polymers T2 according to the invention have amolecular weight (M_(n)) in the range from 6,000 to 50,000, preferablyfrom 8,000 to 40,000, particularly preferably from 8,000 to 35,000,g/mol, a viscosity number in the range from 30 to 450, preferably from50 to 400, g/ml (measured in o-dichlorobenzene/phenol (50/50 ratio byweight) at a concentration of 0.5% by weight of polymer T2 at 25° C.)and a melting point in the range from 50 to 255, preferably from 60 to255° C.

The biodegradable polymers T2 are obtained according to the invention byreacting the polyesteramides Q1 with

(e1) 0.01-50, preferably from 0.1 to 40, % by weight, based onpolyesteramide Q1, of the amino carboxylic acid B1 and with

(e2) 0-5, preferably from 0 to 4, mol %, based on component (b1) fromthe preparation of polyesteramide Q1 via polyesteramide P1, of compoundD,

the procedure expediently being similar to the reaction ofpolyesteramide P1 with amino carboxylic acid B1 to give polyesteramideQ2.

The biodegradable polymers T3 according to the invention have amolecular weight (M_(n)) in the range from 6,000 to 50,000, preferablyfrom 8,000 to 40,000, particularly preferably from 8,000 to 35,000,g/mol, a viscosity number in the range from 30 to 450, preferably from50 to 400, g/ml (measured in o-dichlorobenzene/phenol (50/50 ratio byweight) at a concentration of 0.5% by weight of polymer T3 at 25° C.)and a melting point in the range from 50 to 255, preferably from 60 to255° C.

The biodegradable polymers T3 are obtained according to the invention byreacting (f1) polyesteramide P2, or (f2) a mixture consistingessentially of polyesteramide P1 and 0.01-50, preferably from 0.1 to 40,% by weight, based on polyesteramide P1, of amino carboxylic acid B1, or(f3) a mixture consisting essentially of polyesteramides P1 which differfrom one another in composition, with

0.1-5, preferably from 0.2 to 4, particularly preferably from 0.3 to2.5, % by weight, based on the amount of polyesteramides used, ofdivinyl ether C1 and

with 0-5, preferably from 0 to 4, mol %, based on the particular molaramounts of component (b1) used to prepare the polyesteramides (f1) to(f3) used, of compound D, the reactions expediently being carried out ina similar way to the polyesteramides Q1 from the polyesteramides P1 andthe divinyl ethers C1.

Preferred biodegradable polyesteramides P2 have a molecular weight(M_(n)) in the range from 4,000 to 40,000, preferably from 5,000 to35,000, particularly preferably from 8,000 to 35,000, g/mol, a viscositynumber in the range from 30 to 450, preferably from 50 to 400, g/ml(measured in o-dichlorobenzene/phenol (50/50 ratio by weight) at aconcentration of 0.5% by weight of polyesteramide P2 at 25° C.) and amelting point in the range from 50 to 255, preferably from 60 to 255° C.

The biodegradable polyesteramides P2 are generally obtained by reactinga mixture consisting essentially of

(g1) a mixture consisting essentially of

35-95, preferably from 45 to 80, particularly preferably from 45 to 70,mol % of adipic acid or ester-forming derivatives thereof or mixturesthereof,

5-65, preferably from 20 to 55, particularly preferably from 30 to 55,mol % of terephthalic acid or ester-forming derivatives thereof ormixtures thereof, and

0-5, preferably from 0 to 3, particularly preferably from 0.1 to 2, mol% of a compound containing sulfonate groups,

where the total of the individual mole percentages is 100 mol %,

(g2) mixture (b2),

where the molar ratio (g1) to (g2) is chosen in the range from 0.4:1 to1.5:1, preferably from 0.6:1 to 1.1:1,

(g3) from 0.01 to 40, preferably from 0.1 to 30, % by weight, based oncomponent (g1) of an amino carboxylic acid B1, and

(g4) from 0 to 5, preferably from 0 to 4, particularly preferably from0.01 to 3.5, mol %, based on component (g1), of compound D.

The low molecular weight and cyclic derivatives of the amino carboxylicacid B1 are particularly preferred for preparing polyesteramide P2.

The biodegradable polyesteramides P2 are expediently prepared in asimilar way to the polyesteramides P1, it being possible to add theamino carboxylic acid B1 both at the start of the reaction and after theesterification or transesterification stage.

In a preferred embodiment, polyesteramides P2 whose repeating units arerandomly distributed in the molecule are employed.

However, it is also possible to employ polyesteramides P2 whose polymerchains have block structures. Polyesteramides P2 of this type cangenerally be obtained by appropriate choice, in particular of themolecular weight, of the amino carboxylic acid B1. Thus, according toobservations to date, there is generally only incompletetransesterification when a high molecular weight amino carboxylic acidB1 is used, in particular with a p of above 10, for example even in thepresence of the inactivators described above (see J. of Appl. Polym.Sci. 32 (1986) 6191-6207 and Makromol. Chemie. 136 (1970) 311-313). Ifrequired, the reaction can also be carried out in solution using thesolvents mentioned for the preparation of the polymers T1 from thepolyesteramides Q2 and the divinyl ethers C1.

The biodegradable thermoplastic molding compositions T4 are obtainedaccording to the invention by mixing in a conventional way, preferablywith the addition of conventional additives such as stabilizers,processing aids, fillers etc. (see J. of Appl. Polym. Sci. 32 (1986)6191-6207; WO 92/0441; EP 515203; Kunststoff-Handbuch, Vol. 3/1, CarlHanser Verlag, Munich, 1992, pages 24-28).

(h1) 99.5-0.5% by weight of polyesteramides Q1 with

(h2) 0.5-99.5% by weight of hydroxy carboxylic acid H1 of the generalformula IVa or IVb ##STR5## where x is an integer from 1 to 1,500,preferably from 1 to 1,000, and y is 1, 2, 3 or 4, preferably 1 and 2,and M is a radical selected from the group consisting of phenylene,--(CH₂)_(z) --, where z is an integer from 1, 2, 3, 4 or 5, preferably 1or 5, --C(R²)H-- and --C(R²)HCH₂, where R² is methyl or ethyl.

The hydroxy carboxylic acid H1 employed in a preferred embodiment is:glycolic acid, D-, L- or D,L-lactic acid, 6-hydroxyhexanoic acid, thecyclic derivatives thereof such as glycolide (1,4-dioxane-2,5-dione),D-, L-dilactide (3,6-dimethyl-1,4-dioxane-2,5-dione), p-hydroxybenzoicacid and the oligomers and polymers thereof, such aspoly-3-hydroxybutyric acid, polyhydroxyvaleric acid, polylactide(obtainable as EcoPLA® (from Cargill) for example) and a mixture ofpoly-3-hydroxybutyric acid and polyhydroxyvaleric acid (the latter isobtainable from Zeneca under the name Biopol®).

In a preferred embodiment, high molecular weight hydroxy carboxylicacids H1 such as polycaprolactone or polylactide or polyglycolide with amolecualr weight (M_(n)) in the range from 10,000 to 150,000, preferablyfrom 10,000 to 100,000, g/mol are employed.

WO 92/0441 and EP-A 515203 disclose that high molecualr weightpolylactide without added plasticizers is too brittle for mostapplications. It is possible in a preferred embodiment to prepare ablend starting from 0.5-20, preferably from 0.5 to 10, % by weight ofpolyester and 99.5-80, preferably from 99.5 to 90, % by weight ofpolylactide, which displays a distinct improvement in the mechanicalproperties, for example an increase in the impact strength, comparedwith pure polylactide.

Another preferred embodiment relates to a blend obtainable by mixingfrom 99.5 to 40, preferably from 99.5 to 60, % by weight ofpolyesteramide Q1 and from 0.5 to 60, preferably from 0.5 to 40, % byweight of a high molecular weight hydroxy carboxylic acid B1,particularly preferably polylactide, polyglycolide, polycaprolactone andpolyhydroxybutyric acid. Blends of this type are completelybiodegradable and, according to observations to date, have very goodmechanical properties.

According to observations to date, the thermoplastic moldingcompositions T4 according to the invention are preferably obtained byobserving short mixing times, for example when carrying out the mixingin an extruder. It is also possible to obtain molding compositions whichhave predominantly blend structures by choice of the mixing parameters,in particular the mixing time and, if required, the use of inactivators,ie. it is possible to control the mixing process so thattransesterification reactions can also take place at least partly.

In another preferred embodiment it is possible to replace 0-50,preferably 0-30, mol % of the adipic acid or the ester-formingderivatives thereof or the mixtures thereof by at least one otheraliphatic C₄ -C₁₀ - or cycloaliphatic C₅ -C₁₀ -dicarboxylic acid ordimer fatty acids such as succinic acid, glutaric acid, pimelic acid,suberic acid, azelaic acid or sebacic acid or an ester derivative suchas the di-C₁ -C₆ -alkyl esters thereof or the anhydrides thereof such assuccinic anhydride, or mixtures thereof, preferably succinic acid,succinic anhydride, sebacic acid, dimer fatty acid and di-C₁ -C₆ -alkylesters such as dimethyl, diethyl, di-n-propyl, diisobutyl, di-n-pentyl,dineopentyl, di-n-hexyl esters thereof, especially dimethyl succinate.

A particularly preferred embodiment relates to the use as component (b1)of the mixture, described in EP-A 7445, of succinic acid, adipic acidand glutaric acid and the C₁ -C₆ -alkyl esters thereof, especially thedimethyl esters and diisobutyl esters thereof.

In another preferred embodiment it is possible to replace 0-50,preferably 0-40, mol % of the terephthalic acid or the ester-formingderivatives thereof, or the mixtures thereof, by at least one otheraromatic dicarboxylic acid such as isophthalic acid, phthalic acid or2,6-naphthalenedicarboxylic acid, preferably isophthalic acid, or anester derivative such as a di-C₁ -C₆ -alkyl ester, in particular thedimethyl ester, or mixtures thereof.

It should be noted in general that the various polymers according to theinvention can be worked up in a conventional way by isolating thepolymers or, in particular if it is wished to react the polyesteramidesP1, P2, Q2 and Q1 further, by not isolating the polymers but immediatelyprocessing them further.

The polymers according to the invention can be applied to coatingsubstrates by rolling, spreading, spraying or pouring. Preferred coatingsubstrates are those which are compostable or rot such as moldings ofpaper, cellulose or starch.

The polymers according to the invention can also be used to producemoldings which are compostable. Moldings which may be mentioned by wayof example are: disposable articles such as crockery, cutlery, refusesacks, sheets for agriculture to advance harvesting, packaging sheetsand vessels for growing plants.

It is furthermore possible to spin the polymers according to theinvention into threads in a conventional way. The threads can, ifrequired, be stretched, stretch-twisted, stretch-wound, stretch-warped,stretch-sized and stretch-texturized by customary methods. Thestretching to flat yarn can moreover take place in the same working step(fully drawn yarn or fully oriented yarn) or in a separate step. Thestretch warping, stretch sizing and stretch texturizing are generallycarried out in a working step separate from the spinning. The threadscan be further processed to fibers in a conventional way. Sheet-likestructures can then be obtained from the fibers by weaving or knitting.

The moldings, coating compositions and threads etc. described above can,if required, also contain fillers which can be incorporated during thepolymerization process at any stage or subsequently, for example in themelt of the polymers according to the invention.

It is possible to add from 0 to 80% by weight of fillers, based on thepolymers according to the invention. Examples of suitable fillers arecarbon black, starch, lignin powder, cellulose fibers, natural fiberssuch as sisal and hemp, iron oxides, clay minerals, ores, calciumcarbonate, calcium sulfate, barium sulfate and titanium dioxide. Thefillers can in some cases also contain stabilizers such as tocopherol(vitamin E), organic phosphorus compounds, mono-, di- and polyphenols,hydroquinones, diarylamines, thioethers, UV stabilizers, nucleatingagents such as talc, and lubricants and mold release agents based onhydrocarbons, fatty alcohols, higher carboxylic acids, metal salts ofhigher carboxylic acids such as calcium and zinc stearate, and montanwaxes. Such stabilizers etc. are described in detail inKunststoff-Handbuch, Vol. 3/1, Carl Hanser Verlag, Munich, 1992, pages24-28.

The polymers according to the invention can additionally be colored inany desired way by adding organic or inorganic dyes. The dyes can alsoin the widest sense be regarded as filler.

A particular application of the polymers according to the inventionrelates to the use as compostable sheet or a compostable coating asouter layer of diapers. The outer layer of the diapers effectivelyprevents penetration by liquids which are absorbed inside the diaper bythe fluff and superabsorbers, preferably by biodegradablesuperabsorbers, for example based on crosslinked polyacrylic acid orcrosslinked polyacrylamide. It is possible to use a web of a cellulosematerial as inner layer of the diaper. The outer layer of the describeddiapers is biodegradable and thus compostable. It disintegrates oncomposting so that the entire diaper rots, whereas diapers provided withan outer layer of, for example, polyethylene cannot be composted withoutprevious reduction in size or elaborate removal of the polyethylenesheet.

Another preferred use of the polymers and molding compositions accordingto the invention relates to the production of adhesives in aconventional way (see, for example, Encycl. of Polym. Sci. and Eng.Vol.1, "Adhesive Compositions", pages 547-577). The polymers and moldingcompositions according to the invention can also be processed asdisclosed in EP-A 21042 using suitable tackifying thermoplastic resins,preferably natural resins, by the methods described therein. Thepolymers and molding compositions according to the invention can also befurther processed as disclosed in DE-A 4 234 305 to solvent-freeadhesive systems such as hot melt sheets.

Another preferred application relates to the production of completelydegradable blends with starch mixtures (preferably with thermoplasticstarch as described in WO 90/05161) in a similar process to thatdescribed in DE-A 42 37 535. The polymers and thermoplastic moldingcompositions according to the invention can, according to observationsto date, because of their hydrophobic nature, their mechanicalproperties, their complete biodegradability, their good compatibilitywith thermoplastic starch and not least because of their favorable rawmaterial basis, advantageously be employed as synthetic blend component.

Further applications relate, for example, to the use of the polymersaccording to the invention in agricultural mulch, packaging material forseeds and nutrients, substrate in adhesive sheets, baby pants, pouches,bed sheets, bottles, boxes, dust bags, labels, cushion coverings,protective clothing, hygiene articles, handkerchiefs, toys and wipes.

Another use of the polymers and molding compositions according to theinvention relates to the production of foams, generally by conventionalmethods (see EP-A 372 846; Handbook of Polymeric foams and FoamTechnology, Hanser Publisher, Munich, 1991, pages 375-408). Thisnormally entails the polymer or molding composition according to theinvention being initially melted, if required with the addition of up to5% by weight of compound D, preferably pyromellitic dianhydride andtrimellitic anhydride, then a blowing agent being added and theresulting mixture being exposed to reduced pressure by extrusion,resulting in foaming.

The advantages of the polymers according to the invention over knownbiodegradable polymers are a favorable raw material basis with readilyavailable starting materials such as adipic acid, terephthalic acid andconventional diols, interesting mechanical properties due to thecombination of "hard" (owing to the aromatic dicarboxylic acids such asterephthalic acid) and "soft" (owing to the aliphatic dicarboxylic acidssuch as adipic acid) segments in the polymer chain and the variation inuses due to simple modifications, a satisfactory degradation bymicroorganisms, especially in compost and soil, and a certain resistanceto microorganisms in aqueous systems at room temperature, which isparticularly advantageous for many applications. The randomincorporation of the aromatic dicarboxylic acids of component (b1) invarious polymers makes the biological attack possible and thus achievesthe desired biodegradability.

A particular advantage of the polymers according to the invention isthat it is possible by tailoring the formulations to optimize both thebiodegradation and the mechanical properties for the particularapplication.

It is furthermore possible depending on the preparation processadvantageously to obtain polymers with predominantly random distributionof monomer units, polymers with predominantly block structures andpolymers with predominantly blend structure or blends.

EXAMPLES Abbreviations

TTB: Titanium tetrabutoxide

DMT: Dimethyl terephthalate

Preparation of a Polyesteramide Q1_(a)

The preparation took place in three steps via two precursors.

Precursor 1_(a)

4.672 kg of 1,4-butanediol, 7.000 kg of adipic acid and 50 g of tindioctoate were heated under inert gas (nitrogen) to 230-240° C. Aftermost of the water formed in the reaction had distilled out, 10 g of TTBwere added. As soon as the acid number AN had fallen below 1, the excessbutanediol was distilled out under reduced pressure until the OH numberreached about 56.

Precursor 2_(a)

58.5 g of DMT were heated with 36.5 g of ethanolamine while stirringslowly under a nitrogen atmosphere to 180° C. After 30 min, 360 g ofprecursor 1, 175 g of DMT, 0.65 g of pyromellitic dianhydride, 340 g of1,4-butanediol and 1 g of TTB were added under a nitrogen atmosphere.The methanol and water formed during the transesterification wereremoved by distillation. The mixture was heated to 230° C. over thecourse of 3 h while increasing the stirring speed and, after 2 h, 0.4 gof 50% strength aqueous phosphorous acid was added. Over the course of 2h, the pressure was reduced to 5 mbar and was then kept below 2 mbar andat 240° C. for 45 min, during which the excess 1,4-butanediol distilledout. An elastic, pale brown product was obtained.

OH number: 15 mg KOH/g

AN: below 1 mg KOH/g

prim. amine: below 0.1 g/100 g.

DSC measurements revealed two melting points at 64 and 88° C. and aglass transition temperature of -31° C.

200 g of the precursor 2_(a) were cooled to 170° C., and 3.8 g of1,4-butanediol divinyl ether were added in 3 portions over the course of40 min. The increase in molecular weight was evident from the distinctincrease in the melt viscosity.

OH number: 4 mg KOH/g

AN: below 1 mg KOH/g.

Preparation of Polyesteramide Q1_(b)

The preparation took place in three steps starting from precursor 1_(a).

Precursor 2_(b)

240 g of DMT were heated with 69.7 g of hexamethylenediamine and 6.1 gof ethanolamine while stirring slowly under a nitrogen atmosphere to180° C. After 30 min, 360 g of precursor 1_(a), 8 g of dimethyl sodiumsulfoisophthalate, 340 g of 1,4-butanediol and 1 g of TTB were addedunder a nitrogen atmosphere. The methanol formed during thetransesterification was removed by distillation. The mixture was heatedto 230° C. over the course of 3 h while increasing the stirring speedand, after 2 h, 0.4 g of 50% strength aqueous phosphorous acid wasadded. The pressure was reduced stepwise to 5 mbar in the course of 2 hand then kept at below 2 mbar and at 230° C. for 45 min, during whichthe excess 1,4-butanediol distilled out. An elastic, light brown productwas obtained.

OH number: 17 mg KOH/g

AN: 2.4 mg KOH/g

prim. amine: below 0.1 g/100 g

DSC measurements revealed a melting point at 121° C. and a glasstransition temperature of -35° C.

200 g of precursor 2_(b) were cooled to 170° C., and 4.4 g of1,4-butanediol divinyl ether were added in 3 portions over the course of40 min. The increase in molecular weight was evident from the distinctincrease in the melt viscosity.

OH number: 5 mg KOH/g

AN: below 1 mg KOH/g

Preparation of a Polyesteramide P2_(c)

The preparation took place in three steps starting from precursor 1_(a).

Precursor 2_(c)

360.4 g of precursor 1_(a), 233 g of DMT, 340 g of 1,4-butanediol, 6.1 gof ethanolamine, 62.5 g of an extracted and dried polyamide with lessthan 0.4% by weight of residual extract and a viscosity number of 85(eg. Ultramid® B15 from BASF) and 1 g of TTB were heated under anitrogen atmosphere while stirring slowly to 180° C. The methanol formedduring the transesterification was distilled out. The mixture was heatedto 230° C. over the course of 3 h while increasing the stirring speed.After 2 h, 0.4 g of 50% strength aqueous phosphorous acid was added. Thepressure was reduced to 5 mbar over the course of 2 h and then keptbelow 2 mbar and at 240° C. for 1 h, during which the excess1,4-butanediol distilled out.

OH number: 9 mg KOH/g

AN: 0.6 mg KOH/g

Viscosity number: 98.9

DSC measurements revealed two melting points at 104 and 215° C. and aglass transition temperature at -37° C.

200 g of precursor 2_(c) were cooled to 170° C., and 2.4 g of1,4-butanediol divinyl ether were added in 3 portions over the course of40 min. The increase in molecular weight was evident from the distinctincrease in the melt viscosity.

OH number: 4 mg KOH/g

AN: below 1 mg KOH/g

Enzyme assay with Rhizopus arrhizus: ΔDOC: 272 mg/l/ΔDOC (PCL): 2019.

Methods of Measurement

Enzyme Assay

The polymers were cooled with liquid nitrogen or dry ice in a mill andfinely ground (the rate of enzymatic breakdown increases with thesurface area of the milled material). The enzyme assay was carried outby placing 30 mg of finely ground polymer powder and 2 ml of a 20 mmol/laqueous K₂ HPO₄ /KH₂ PO₄ buffer solution (pH: 7.0) in an Eppendorf tube(2 ml) and equilibrated on a rotator at 37° C. for 3 h. Subsequently 100units of lipase from either Rhizopus arrhizus, Rhizopus delemar orPseudomonas pl. were added and incubated on the rotator (250 rpm) at 37°C. for 16 h. The reaction mixture was then filtered through a Millipore®membrane (0.45 μm), and the DOC (dissolved organic carbon) of thefiltrate was measured. Similar DOC measurements were carried out in onecase only with buffer and enzyme (as enzyme control) and in one caseonly with buffer and sample (as blank).

The ΔDOC values found (DOC (sample+enzyme)--DOC (enzyme control)--DOC(blank value)) can be regarded as a measure of the enzymaticdegradability of the samples. They are presented in each case comparingwith a measurement with powder from polycaprolactone® Tone P 787 (UnionCarbide). It must be remembered in the assessment that these are notabsolutely quantifiable data. The connection between the surface area ofthe milled material and the speed of enzymatic breakdown has beenreferred to above. Furthermore the enzyme activities may also vary.

The hydroxyl number (OH number) and acid number (AN) were determined bythe following methods:

(a) Determination of the Apparent Hydroxyl Number

10 ml of toluene and 9.8 ml of acetylating reagent (see below) wereadded to about 1 to 2 g of accurately weighed test substance and heatedat 95° C. with stirring for 1 h. Then 5 ml of distilled water wereadded. After cooling to room temperature, 50 ml of tetrahydrofuran (THF)were added, and potentiographic titration to the turning point wascarried out with standard ethanolic KOH solution.

The experiment was repeated without test substance (blank sample).

The apparent OH number was then found from the following formula:

apparent OH number c×t×56.1(V2-V1)/m (in mg KOH/g)

where c=amount of substance concentration of the standard ethanolic KOHsolution in mol/l

t=titer of the standard ethanolic KOH solution

m=weight of test substance in mg

V1=ml of standard solution used with test substance

V2=ml of standard solution used without test substance.

Reagents used:

standard ethanolic KOH solution, c=0.5 mol/l, titer 0.9933 (Merck, Cat.No. 1.09114)

acetic anhydride, analytical grade (Merck, Cat. No. 42)

pyridine, analytical grade (Riedel de Haen, Cat. No. 33638)

acetic acid, analytical grade (Merck, Cat. No. 1.00063)

acetylating reagent: 810 ml of pyridine, 100 ml of acetic anhydride and9 ml of acetic acid

water, deionized

THF and toluene

(b) Determination of the Acid Number (AN)

About 1 to 1.5 g of test substance were weighed accurately, 10 ml oftoluene and 10 ml of pyridine were added, and the mixture was thenheated to 95° C. After dissolving, the solution was cooled to roomtemperature, 5 ml of water and 50 ml of THF were added, and titrationwas carried out with 0.1 N standard ethanolic KOH solution.

The determination was repeated without test substance (blank sample).

The acid number was then found from the following formula:

AN=c×t×56.1(V1-V2)/m (in mg KOH/g)

where

c=amount of substance concentration of the standard ethanolic KOHsolution in mol/l

t=titer of the standard ethanolic KOH solution

m=weight of test substance in mg

V1=ml of standard solution used with test substance

V2=ml of standard solution used without test substance.

Reagents used:

standard ethanolic KOH solution, c=0.1 mol/l, titer=0.9913 (Merck, Cat.No. 9115)

pyridine, analytical grade (Riedel de Haen, Cat. No. 33638)

water, deionized

THF and toluene

(c) Determination of the OH number

The OH number is obtained from the sum of the apparent OH number and theAN:

OH number=apparent OH number+AN

The viscosity number (VN) was measured in o-dichlorobenzene/phenol(50/50 ratio by weight) at a concentration of 0.5% by weight of polymerat 25° C.

The DSC measurements were carried out with a DuPont DSC 912apparatus+thermal analyzer 990. The temperature and enthalpy calibrationtook place in a conventional way. The weight of sample was typically 13mg. The heating and cooling rates were 20 K/min. The samples weremeasured under the following conditions: 1. Heating run on samples inthe state supplied, 2. Rapid cooling from the melt, 3. Heating run onthe samples cooled from the melt (samples from 2). The second DSC runsin each case were used to compare various samples after a uniformthermal history.

What is claimed is:
 1. A biodegradable polyesteramide Q1 with amolecular weight (M_(n)) of from 5,000 to 50,000 g/mol, a viscositynumber of from 30 to 450 g/ml (measured in o-dichlorobenzene/phenol(50/50 ratio by weight) at a concentration of 0.5% by weight ofpolyesteramide Q1 at 25° C.) and a melting point of from 50 to 220° C.,obtained by reacting a mixture consisting essentially of(a1) from 95 to99.9% by weight of a polyesteramide P1 obtained by reacting a mixtureconsisting essentially of (b1) a mixture consisting essentially of35-95mol % of adipic acid or ester-forming derivatives thereof or mixturesthereof, 5-65 mol % of terephthalic acid or ester-forming derivativesthereof or mixtures thereof, and 0-5 mol % of a compound containingsulfonate groups, where the total of the individual mole percentages is100 mol %, and (b2) a mixture consisting essentially of(b21) 99.5-0.5mol % of a dihydroxy compound selected from the group consisting of C₂-C₆ -alkanediols and C₅ -C₁₀ -cycloalkanediols, (b22) 0.5-99.5 mol % ofan amino-C₂ -C₁₂ -alkanol or of an amino-C₅ -C₁₀ -cycloalkanol, and(b23) 0-50 mol % of a diamino-C₁ -C₈ -alkane, (b24) 0-50 mol % of a2,2'-bisoxazoline of the general formula I ##STR6## where R¹ is a singlebond, a (CH₂)_(q) -alkylene group with q=2, 3 or 4, or a phenylenegroup, where the total of the individual mole percentages is 100 mol %,and where the molar ratio of (b1) to (b2) is from 0.4:1 to 1.5:1, withthe proviso that the polyesteramide P1 has a molecular weight (M_(n)) offrom 4,000 to 40,000 g/mol, a viscosity number of from 30 to 350 g/ml(measured in o-dichlorobenzene/phenol (50/50 ratio by weight) at aconcentration of 0.5% by weight of polyesteramide P1 at 25° C.) and amelting point of from 50 to 220° C., and with the further proviso thatfrom 0 to 5 mol %, based on the molar amount of component (a1) used , ofat least one compound D having three to six hydroxyl groups or carboxylgroups or mixtures thereof or anhydrides or dianhydrides of the carboxylgroups are used to prepare the polyesteramide P1, (a2) from 0.1 to 5% byweight of a divinyl ether C1 and (a3) from 0 to 5 mol %, based oncomponent (b1) from the preparation of P1 of at least one compound Dhaving three to six hydroxyl groups or carboxyl groups or mixturesthereof or anhydrides or dianhydrides of the carboxyl groups.
 2. Abiodegradable polymer T1 with a molecular weight (M_(n)) of from 6,000to 50,000 g/mol, with a viscosity number of from 30 to 450 g/ml(measured in o-dichlorobenzene/phenol (50/50 ratio by weight) at aconcentration of 0.5% by weight of polymer T1 at 25° C.) and a meltingpoint of from 50 to 255° C., obtained by reacting a polyesteramide Q2with a molecular weight (M_(n)) of from 5,000 to 50,000 g/mol, aviscosity number of from 30 to 450 g/ml (measured ino-dichlorobenzene/phenol (50/50 ratio by weight) at a concentration of0.5% by weight of polymer Q2 at 25° C.) and a melting point of from 50to 255° C., obtained by reacting a mixture consisting essentially of(c1)polyesteramide P1, as claimed in claim 1, (c2) 0.01-50% by weight, basedon (c1), of an amino carboxylic acid, where the amino carboxylic acid isselected from the group consisting of the natural amino acids,polyamides with a molecular weight not exceeding 18,000 g/mol, obtainedby polycondensation of a dicarboxylic acid with 4 to 6 carbon atoms anda diamine with 4 to 10 carbon atoms and compounds which are defined bythe formulae IIa and IIb ##STR7## where p is an integer from 1 to 1,500and r is an integer from 1 to 4, and G is a radical which is selectedfrom the group consisting of phenylene, --(CH₂)_(n) --, where n is aninteger from 1 to 12, --C(R²)H-- and --C(R²)HCH₂, where R² is methyl orethyl, and polyoxazolines with repeating unit III ##STR8## where R³ ishydrogen, C₁ -C₆ -alkyl, C₅ -C₈ -cycloalkyl, phenyl which isunsubstituted or substituted up to three times by C₁ -C₄ -alkyl groups,or tetrahydrofuryl, (c3) 0-5 mol %, based on component (b1) from thepreparation of P1, of at least one compound D having three to sixhydroxyl groups or carboxyl groups or mixtures thereof or anhydrides ordianhydrides of the carboxyl groups,with (d1) 0.1-5% by weight, based onthe polyesteramide Q2, of divinyl ether C1 and with (d2) 0-5 mol %,based on component (b1) which was used for the preparation ofpolyesteramide Q2, of at least one compound D having three to sixhydroxyl groups or carboxyl groups or mixtures thereof or anhydrides ordianhydrides of the carboxyl groups.
 3. A biodegradable polymer T2 witha molecular weight (M_(n)) of from 6,000 to 50,000 g/mol, with aviscosity number of from 30 to 450 g/ml (measured ino-dichlorobenzene/phenol (50/50 ratio by weight) at a concentration of0.5% by weight of polymer T2 at 25° C.) and a melting point of from 50to 255° C., obtained by reacting a polyesteramide Q1 with a molecularweight (M_(n)) of from 5,000 to 50,000 g/mol, a viscosity number of from30 to 450 g/ml (measured in o-dichlorobenzene/phenol (50/50 ratio byweight) at a concentration of 0.5% by weight of polymer Q1 at 25° C.)and a melting point of from 50 to 220° C., obtained by reacting amixture consisting essentially of(a1) from 95 to 99.9% by weight of apolyesteramide P1 as claimed in claim 1, (a2) from 0.1 to 5% by weightof a divinyl ether C1 and (a3) from 0 to 5 mol %, based on the molaramount of component (b1) used for the preparation of P1, of at least onecompound D having three to six hydroxyl groups or carboxyl groups ormixtures thereof or anhydrides or dianhydrides of the carboxyl groups,with (e1) 0.01-50% by weight, based on polyesteramide Q1, of aminocarboxylic acid B1 where the amino carboxylic acid is selected from thegroup consisting of the natural amino acids, polyamides with a molecularweight not exceeding 18,000 g/mol, obtained by polycondensation of adicarboxylic acid with 4 to 6 carbon atoms and a diamine with 4 to 10carbon atoms and compounds which are defined by the formulae IIa and IIb##STR9## where p is an integer from 1 to 1,500 and r is an integer from1 to 4, and G is a radical which is selected from the group consistingof phenylene, --(CH₂)--_(n) --, where n is an integer from 1 to 12,--C(R²)H-- and --C(R²)HCH₂, where R² is methyl or ethyl, andpolyoxazolines with repeating unit III ##STR10## where R³ is hydrogen,C₁ -C₈ -alkyl, C₅ -C₈ cycloalkyl, phenyl which is unsubstituted orsubstituted up to three times by C₁ -C₄ -alkyl groups, ortetrahydrofuryl, and with (e2) 0-5 mol %, based on the molar amount ofcomponent (b1) used for the preparation of polyesteramide Q1, of atleast one compound D having three to six hydroxyl groups or carboxylgroups or mixtures thereof or anhydrides or dianhydrides of the carboxylgroups.
 4. A biodegradable polymer T3 with a molecular weight (M_(n)) offrom 6,000 to 50,000 g/mol, with a viscosity number of from 30 to 450g/ml (measured in o-dichlorobenzene/phenol (50/50 ratio by weight) at aconcentration of 0.5% by weight of polymer T3 at 25° C.) and a meltingpoint of from 50 to 255° C., obtained by reacting(f1) polyesteramide P2with a molecular weight (M_(n)) of from 4,000 to 40,000 g/mol, aviscosity number of from 30 to 450 g/ml (measured ino-dichlorobenzene/phenol (50/50 ratio by weight) at a concentration of0.5% by weight of polyesteramide P2 at 25° C.) and a melting point offrom 50 to 255° C., obtained by reacting a mixture consistingessentially of (g1) a mixture consisting essentially of35-95 mol % ofadipic acid or ester-forming derivatives thereof or mixtures thereof,5-65 mol % of terephthalic acid or ester-forming derivatives thereof ormixtures thereof, and 0-5 mol % of a compound containing sulfonategroups,where the total of the individual mole percentages is 100 mol %,(g2) mixture (b2), a mixture consisting essentially of(b21) 99.5-0.5 mol% of a dihydroxy compound selected from the group consisting of C₂ -C₆-alkanediols and C₅ -C₁₀ -cycloalkanediols, (b22) 0.5-99.5 mol % of anamino-C₂ -C₁₂ -alkanol or of an amino-C₅ -C₁₀ -cycloalkanol, and (b23)0-50 mol % of a diamino-C₁ -C₈ -alkane, (b24) 0-50 mol % of a2,2'-bisoxazoline of the general formula I ##STR11## where R¹ is asingle bond, a (CH₂)_(q) -alkylene group with q=2, 3 or 4, or aphenylene group, where the total of the individual mole percentages is100 mol %, and where the molar ratio of (g1) to (g2) is from 0.4:1 to1.5:1, (g3) from 0.01 to 40 mol %, based on component (g1), of aminocarboxylic acid where the amino carboxylic acid is selected from thegroup consisting of the natural amino acids, polyamides with a molecularweight not exceeding 18,000 g/mol, obtained by polycondensation of adicarboxylic acid with 4 to 6 carbon atoms and a diamine with 4 to 10carbon atoms and compounds which are defined by the formulae IIa and IIb##STR12## where p is an integer from 1 to 1,500 and r is an integer from1 to 4, and G is a radical which is selected from the group consistingof phenylene, --(CH₂)_(n) --, where n is an integer from 1 to 12,--C(R²)H-- and --C(R²)HCH₂, where R² is methyl or ethyl, andpolyoxazolines with repeating unit III ##STR13## where R³ is hydrogen,C₁ -C₆ -alkyl, C₅ -C₈ -cycloalkyl, phenyl which is unsubstituted orsubstituted up to three times by C₁ -C₄ -alkyl groups, ortetrahydrofuryl, (g4) from 0 to 5 mol %, based on component (g1), of atleast one compound D having three to six hydroxyl groups or carboxylgroups or mixtures thereof or anhydrides or dianhydrides of the carboxylgroups or (f2) a mixture consisting essentially of polyesteramide P1 asclaimed in claim 1 and 0.01-50% by weight, based on polyesteramide P1,of amino carboxylic acid, or (f3) a mixture consisting essentially ofpolyesteramides P1, which differ from one another in composition, with0.1-5% by weight, based on the amount of polyesteramides used, ofdivinyl ether C1 and with 0-5 mol %, based on the particular molaramounts of component (b1) used to prepare the polyester (f1) to (f3)used, of at least one compound D having three to six hydroxyl groups orcarboxyl groups or mixtures thereof or anhydrides or dianhydrides of thecarboxyl groups.
 5. A biodegradable thermoplastic molding composition T4obtained by mixing in a conventional way(h1) 99.5-0.5% by weight ofpolyesteramide Q1 with a molecular weight (M_(n)) of from 5,000 to50,000 g/mol, a viscosity number of from 30 to 450 g/ml (measured ino-dichlorobenzene/phenol (50/50 ratio by weight) at a concentration of0.5% by weight of polyesteramide Q1 at 25° C.) and a melting point offrom 50 to 220° C., obtained by reacting a mixture consistingessentially of (a1) from 95 to 99.9% by weight of a polyesteramide P1 asclaimed in claim 1, (a2) from 0-1 to 5% by weight of a divinyl ether C1and (a3) from 0 to 5 mol %, based on the molar amount of component (b1)used for the preparation of P1, of at least one compound D having threeto six hydroxyl groups or carboxyl groups or mixtures thereof oranhydrides or dianhydrides of the carboxyl groups, with (h2) 0.5-99.5%by weight of a hydroxy carboxylic acid of the general formula IVa or IVb##STR14## where x is an integer from 1 to 1,500 and y is an integer from1 to 4, and M is a radical selected from the group consisting ofphenylene, --(CH₂)_(z) --, where z is an integer from 1 to 5 ,--C(R²)H-- and --C(R²)HCH₂, where R² is methyl or ethyl.
 6. A processfor preparing the biodegradable polyesteramides Q1 with a molecularweight (M_(n)) of from 5,000 to 50,000 g/mol, a viscosity number of from30 to 450 g/ml (measured in o-dichlorobenzene/phenol (50/50 ratio byweight) at a concentration of 0.5% by weight of polyesteramide Q1 at 25°C.) and a melting point of from 50 to 220° C., which comprises in afirst step preparing(a1) polyesteramide P1 obtained by reacting amixture consisting essentially of (b1) a mixture consisting essentiallyof35-95 mol % of adipic acid or ester-forming derivatives thereof ormixtures thereof, 5-65 mol % of terephthalic acid or ester-formingderivatives thereof or mixtures thereof, and 0-5 mol % of a compoundcontaining sulfonate groups, where the total of the individual molepercentages is 100 mol %, and (b2) a mixture consisting essentiallyof(b21) 99.5-0.5 mol % of a dihydroxy compound selected from the groupconsisting of C₂ -C₆ -alkanediols and C₅ -C₁₀ -cycloalkanediols, (b22)0.5-99.5 mol % of an amino-C₂ -C₁₂ -alkanol or of an amino-C₅ -C₁₀-cycloalkanol, and (b23) 0-50 mol % of a diamino-C₁ -C₈ -alkane, (b24)0-50 mol % of a 2,2'-bisoxazoline of the general formula I ##STR15##where R¹ is a single bond, a (CH₂)_(q) -alkylene group with q=2, 3 or 4,or a phenylene group, where the total of the individual mole percentagesis 100 mol %, and where the molar ratio of (b1) to (b2) is from 0.4:1 to1.5:1, with the proviso that the polyesteramide P1 has a molecularweight (M_(n)) of from 4,000 to 40,000 g/mol, a viscosity number of from30 to 350 g/ml (measured in o-dichlorobenzene/phenol (50/50 ratio byweight) at a concentration of 0.5% by weight of polyesteramide P1 at 25°C.) and a melting point of from 50 to 220° C., and with the furtherproviso that from 0 to 5 mol %, based on the molar amount of component(a1) used, of at least one compound D having three to six hydroxylgroups or carboxyl groups or mixtures thereof or anhydrides ordianhydrides of the carboxyl groups are used to prepare thepolyesteramide P1, and in a second step reacting a mixture consistingessentially of from 95 to 99.5% by weight of (a1), (a2) from 0.1 to 5%by weight of divinyl ether C1 and (a3) from 0 to 5 mol %, based on themolar amount of component (b1) used for the preparation of P1, of atleast one compound D having three to six hydroxyl groups or carboxylgroups or mixtures thereof or anhydrides or dianhydrides of the carboxylgroups.
 7. A process for preparing the biodegradable polymers T1 with amolecular weight (M_(n)) of from 6,000 to 50,000 g/mol, with a viscositynumber of from 30 to 450 g/ml (measured in o-dichlorobenzene/phenol(50/50 ratio by weight) at a concentration of 0.5% by weight of polymerT1 at 25° C.) and a melting point of from 50 to 255° C., which comprisesin a first step preparing polyesteramide Q2 with a molecular weight(M_(n)) of from 5,000 to 50,000 g/mol, a viscosity number of from 30 to450 g/ml (measured in o-dichlorobenzene/phenol (50/50 ratio by weight)at a concentration of 0.5% by weight of polymer Q2 at 25° C.) and amelting point of from 50 to 255° C., obtained by reacting a mixtureconsisting essentially of(c1) polyesteramide P1 as claimed in claim 1,(c2) 0.01-50% by weight, based on (c1), of an amino carboxylic acid,where the amino carboxylic acid is selected from the group consisting ofthe natural amino acids, polyamides with a molecular weight notexceeding 18,000 g/mol, obtained by polycondensation of a dicarboxylicacid with 4 to 6 carbon atoms and a diamine with 4 to 10 carbon atomsand compounds which are defined by the formulae IIa and IIb ##STR16##where p is an integer from 1 to 1,500 and r is an integer from 1 to 4,and G is a radical which is selected from the group consisting ofphenylene, --(CH₂)_(n) --, where n is an integer from 1 to 12,--C(R²)H-- and --C(R²)HCH₂, where R² is methyl or ethyl, andpolyoxazolines with repeating unit III ##STR17## where R³ is hydrogen,C₁ -C₆ -alkyl, C₅ -C₈ -cycloalkyl, phenyl which is unsubstituted orsubstituted up to three times by C₁ -C₄ -alkyl groups, ortetrahydrofuryl, (c3) 0-5 mol %, based on component (b1) from thepreparation of P1, of at least one compound D having three to sixhydroxyl groups or carboxyl groups or mixtures thereof or anhydrides ordianhydrides of the carboxyl groups, and in a second step reacting Q2with (d1) 0.1-5% by weight, based on polyesteramide Q2, of divinyl etherC1 and with (d2) 0-5 mol %, based on the molar amount of component (b1)used for the preparation of polyesteramide Q2, of at least one compoundD having three to six hydroxyl groups or carboxyl groups or mixturesthereof or anhydrides or dianhydrides of the carboxyl groups.
 8. Aprocess for preparing the biodegradable polymers T2 with a molecularweight (M_(n)) of from 6,000 to 50,000 g/mol, with a viscosity number offrom 30 to 450 g/ml (measured in o-dichlorobenzene/phenol (50/50 ratioby weight) at a concentration of 0.5% by weight of polymer T2 at 25° C.)and a melting point of from 50 to 255° C., which comprises in a firststep preparing polyesteramide Q1, with a molecular weight molecularweight (M_(n)) of from 5,000 to 50,000 g/mol, a viscosity number of from30 to 450 g/ml (measured in o-dichlorobenzene/phenol (50/50 ratio byweight) at a concentration of 0.5% by weight of polymer Q1 at 25° C.)and a melting point of from 50 to 220° C., obtained by reacting amixture consisting essentially of(a1) from 95 to 99.9% by weight of apolyesteramide P1 obtained by reacting a mixture consisting essentiallyof (b1) a mixture consisting essentially of35-95 mol % of adipic acid orester-forming derivatives thereof or mixtures thereof, - 65 mol % ofterephthalic acid or ester-forming derivatives thereof or mixturesthereof, and 0-5 mol % of a compound containing sulfonate groups, wherethe total of the individual mole percentages is 100 mol %, and (b2) amixture consisting essentially of(b21) 99.5-0.5 mol % of a dihydroxycompound selected from the group consisting of C₂ -C₆ -alkanediols andC₅ -C₁₀ -cycloalkanediols, (b22) 0.5-99.5 mol % of an amino-C₂ -C₁₂-alkanol or of an amino-C₅ -C₁₀ -cycloalkanol, and (b23) 0-50 mol % of adiamino-C₁ -C₈ -alkane, (b24) 0-50 mol % of a 2,2'-bisoxazoline of thegeneral formula I ##STR18## where R¹ is a single bond, a (CH₂)_(q)-alkylene group with q=2, 3 or 4, or a phenylene group, where the totalof the individual mole percentages is 100 mol %, and where the molarratio of (b1) to (b2) is from 0.4:1 to 1.5:1, with the proviso that thepolyesteramide P1 has a molecular weight (M_(n)) of from 4,000 to 40,000g/mol, a viscosity number of from 30 to 350 g/ml (measured ino-dichlorobenzene/phenol (50/50 ratio by weight) at a concentration of0.5% by weight of polyesteramide P1 at 25° C.) and a melting point offrom 50 to 220° C., and with the further proviso that from 0 to 5 mol %, based on the molar amount of component (a1) used, of at least onecompound D having three to six hydroxyl groups or carboxyl groups ormixtures thereof or anhydrides or dianhydrides of the carboxyl groupsare used to prepare the polyesteramide P1, (a2) from 0.1 to 5% by weightof a divinyl ether C1 and (a3) from 0 to 5 mol %, based on the molaramount of component (b1) used for the preparation of P1, of at least onecompound D having three to six hydroxyl groups or carboxyl groups ormixtures thereof or anhydrides or dianhydrides of the carboxyl groups,and in a second step reacting Q1 with (e1) 0.01-50% by weight, based onpolyesteramide Q1, of amino carboxylic acid where the amino carboxylicacid is selected from the group consisting of the natural amino acids,polyamides with a molecular weight not exceeding 18,000 g/mol, obtainedby polycondensation of a dicarboxylic acid with 4 to 6 carbon atoms anda diamine with 4 to 10 carbon atoms and compounds which are defined bythe formulae IIa and IIb ##STR19## where p is an integer from 1 to 1,500and r is an integer from 1 to 4, and G is a radical which is selectedfrom the group consisting of phenylene, --(CH₂)_(n) --, where n is aninteger from 1 to 12, --C(R²)H-- and --C(R²)HCH₂, where R² is methyl orethyl, and polyoxazolines with repeating unit III ##STR20## where R³ ishydrogen, C₁ -C₆ -alkyl, C₅ -C₈ -cycloalkyl, phenyl which isunsubstituted or substituted up to three times by C₁ -C₄ -alkyl groups,or tetrahydrofuryl, and with (e2) 0-5 mol %, based on the molar amountof component (b1) used for the preparation of polyesteramide Q1, of atleast one compound D having three to six hydroxyl groups or carboxylgroups or mixtures thereof or anhydrides or dianhydrides of the carboxylgroups.
 9. A process for preparing the biodegradable polymer T3 with amolecular weight (M_(n)) of from 6,000 to 50,000 g/mol, with a viscositynumber of from 30 to 450 g/ml (measured in o-dichlorobenzene/phenol(50/50 ratio by weight) at a concentration of 0.5% by weight of polymerT3 at 25° C.) and a melting point of from 50 to 255° C., which comprisesin a first step preparing(f1) polyesteramide P2 with a molecular weight(M_(n)) of from 4,000 to 40,000 g/mol, a viscosity number of from 30 to450 g/ml (measured in o-dichlorobenzene/phenol (50/50 ratio by weight)at a concentration of 0.5% by weight of polyesteramide P2 at 25° C.) anda melting point of from 50 to 255° C., obtained by reacting a mixtureconsisting essentially of (g1) a mixture consisting essentially of35-95mol % of adipic acid or ester-forming derivatives thereof or mixturesthereof, 5-65 mol % of terephthalic acid or ester-forming derivativesthereof or mixtures thereof, and 0-5 mol % of a compound containingsulfonate groups,where the total of the individual mole percentages is100 mol %, (g2) mixture (b2), a mixture consisting essentially of(b21)99.5-0.5 mol % of a dihydroxy compound selected from the groupconsisting of C₂ -C₆ -alkanediols and C₅ -C₁₀ -cycloalkanediols, (b22)0.5-99.5 mol % of an amino-C₂ -C₁₂ -alkanol or of an amino-C₅ -C₁₀-cycloalkanol, and (b23) 0-50 mol % of a diamino-C₁ -C₈ -alkane, (b24)0-50 mol % of a 2,2'-bisoxazoline of the general formula I ##STR21##where R¹ is a single bond, a (CH₂)_(q) -alkylene group with q=2, 3 or 4,or a phenylene group, where the total of the individual mole percentagesis 100 mol %, and where the molar ratio of (g1) to (g2) is from 0.4:1 to1.5:1, (g3) from 0.01 to 40 mol %, based on component (g1), of aminocarboxylic acid where the amino carboxylic acid is selected from thegroup consisting of the natural amino acids, polyamides with a molecularweight not exceeding 18,000 g/mol, obtained by polycondensation of adicarboxylic acid with 4 to 6 carbon atoms and a diamine with 4 to 10carbon atoms and compounds which are defined by the formulae IIa and IIb##STR22## where p is an integer from 1 to 1,500 and r is an integer from1 to 4, and G is a radical which is selected from the group consistingof phenylene, --(CH₂)_(n) --, where n is an integer from 1 to 12,--C(R²)H-- and --C(R²)HCH₂, where R² is methyl or ethyl, andpolyoxazolines with repeating unit III ##STR23## where R³ is hydrogen,C₁ -C₆ -alkyl, C₅ -C₈ -cycloalkyl, phenyl which is unsubstituted orsubstituted up to three times by C₁ -C₄ -alkyl groups, ortetrahydrofuryl, (g4) from 0 to 5 mol %, based on component (g1), of atleast one compound D having three to six hydroxyl groups or carboxylgroups or mixtures thereof or anhydrides or dianhydrides of the carboxylgroups or (f2) a mixture consisting essentially of polyesteramide P1obtained by reacting a mixture consisting essentially of (b1) a mixtureconsisting essentially of35-95 mol % of adipic acid or ester-formingderivatives thereof or mixtures thereof, 5-65 mol % of terephthalic acidor ester-forming derivatives thereof or mixtures thereof, and 0-5 mol %of a compound containing sulfonate groups, where the total of theindividual mole percentages is 100 mol %, and (b2) and where the molarratio of (b1) to (b2) is chosen in the range from 0.4:1 to 1.5:1, withthe proviso that the polyesteramide P1 has a molecular weight (M_(n)) offrom 4,000 to 40,000 g/mol, a viscosity number of from 30 to 350 g/ml(measured in o-dichlorobenzene/phenol (50/50 ratio by weight) at aconcentration of 0.5% by weight of polyesteramide P1 at 25° C.) and amelting point of from 50 to 220° C., and with the further proviso thatfrom 0 to 5 mol %, based on the molar amount of component (a1) used, ofat least one compound D having three to six hydroxyl groups or carboxylgroups or mixtures thereof or anhydrides or dianhydrides of the carboxylgroups are used to prepare the polyesteramide P1, and 0.1-50% by weight,based on polyesteramide P1, of amino carboxylic acid, or (f3) a mixtureconsisting essentially of polyesteramide P1 which differ from oneanother in composition, and in a second step reacting (f1) or (f2) or(f3) with 0.1-5% by weight, based on the amount of polyesteramides used,of divinyl ether C1 and with 0-5 mol %, based on the particular molaramounts of component (b1) or (g1) used to prepare the polyesteramides(f1) to (f3) used, of at least one compound D having three to sixhydroxyl groups or carboxyl groups or mixtures thereof or anhydrides ordianhydrides of the carboxyl groups.
 10. A process for preparing thebiodegradable thermoplastic molding compositions T4₁, which comprises ina first step preparing polyetheresteramide Q1 with a molecular weight(M_(n)) of from 5,000 to 50,000 g/mol, a viscosity number of from 30 to450 g/ml (measured in o-dichlorobenzene/phenol (50/50 ratio by weight)at a concentration of 0.5% by weight of polyesteramide Q1 at 25° C.) anda melting point of from 50 to 220° C., obtained by reacting a mixtureconsisting essentially of(a1) from 95 to 99.9% by weight of apolyesteramide P1 obtained by reacting a mixture consisting essentiallyof (b1) a mixture consisting essentially of3- 95mol % of adipic acid orester-forming derivatives thereof or mixtures thereof, 5-65 mol % ofterephthalic acid or ester-forming derivatives thereof or mixturesthereof, and 0-5 mol % of a compound containing sulfonate groups, wherethe total of the individual mole percentages is 100 mol %, and (b2) amixture consisting essentially of(b21) 99.5-0.5 mol % of a dihydroxycompound selected from the group consisting of C₂ -C₆ -alkanediols andC₅ -C₁₀ -cycloalkanediols, (b22) 0.5-99.5 mol % of an amino-C₂ -C₁₂-alkanol or of an amino-C₅ -C₁₀ -cycloalkanol, and (b23) 0-50 mol % of adiamino-C₁ -C₈ -alkane, (b24) 0-50 mol % of a 2,2'-bisoxazoline of thegeneral formula I ##STR24## where R¹ is a single bond, a (CH₂)_(q)-alkylene group with q=2, 3 or 4, or a phenylene group, where the totalof the individual mole percentages is 100 mol %, and where the molarratio of (b1) to (b2) is from 0.4:1 to 1.5:1, with the proviso that thepolyesteramide P1 has a molecular weight (M_(n)) of from 4,000 to 40,000g/mol, a viscosity number of from 30 to 350 g/ml (measured ino-dichlorobenzene/phenol (50/50 ratio by weight) at a concentration of0.5% by weight of polyesteramide P1 at 25° C.) and a melting point offrom 50 to 220° C., and with the further proviso that from 0 to 5 mol %,based on the molar amount of component (a1) used, of at least onecompound D having three to six hydroxyl groups or carboxyl groups ormixtures thereof or anhydrides or dianhydrides of the carboxyl groupsare used to prepare the Polyesteramide P1, (a2) from 0.1 to 5% by weightof a divinyl ether C1 and (a3) from 0 to 5 mol %, based on the molaramount of component (b1) from the preparation of P1, of at least onecompound D having three to six hydroxyl groups or carboxyl groups ormixtures thereof or anhydrides or dianhydrides of the carboxyl groupsand in a second step mixing 99.5-0.5% by weight of polyesteramide Q1with 0.5-99.5% by weight of hydroxy carboxylic acid H1.
 11. Acompostable molding made from biodegradable polyesteramides Q1 asclaimed in claim
 1. 12. A compostable molding made from biodegradablepolyesteramides Q1 as claimed in claim
 1. 13. A biodegradable blend madefrom biodegradable polyesteramides Q1 as claimed in claim 1 and starch.14. A biodegradable foam made from biodegradable polyesteramides Q1 asclaimed in claim
 1. 15. A paper coating composition made frombiodegradable polyesteramides Q1 as claimed in claim 1.